No abstract

In the last 5 years the prevalence of the iPod/Mp3 players has grown exponentially. The use of devices with inear earphones under urban conditions has been reported widely in the press anecdotally. This study compared listening levels for 33 test subjects under quiet conditions and that representative of a London Underground train journey. Calibrated recordings of underground trains running in tunnels were played through a loudspeaker in an anechoic chamber, whilst pop music, rock music or speech podcasts were played through the in-ear earphones. Whilst the participates listened to the iPod, a Binaural Head and Torso simultaneously measured the noise levels through a second set of in-ear earphones. The participants had time to adjust the volume to a comfortable setting on each occasion. Results show very high levels of noise exposure particularly for rock music, 90% of subjects exceeding lower exposure limit within 1 hour of use, when used on the an underground train. The iPod volume setting changed significantly more for the podcast, 22 dBA than for the music 12 dBA on average.